The present invention relates to a target alignment system for use with golf clubs.
In playing the game of golf, it is desirable that the clubface of the golf club which strikes the ball be aligned perpendicular to the intended target path in the direction the ball is to travel as it is struck in order that the ball will be consistently projected to the desired target. Ideally, a golf club would be aligned at address in the proper position and returned to the same position to strike the ball as it is swung. When a golf clubface is misaligned in the address position, the swing then requires a correction factor to return the clubface back to the ideal perpendicular position as the ball is struck. This correction factor makes an already complex precision movement more difficult and introduces additional areas where errors may occur. If the clubface is properly aligned at the address position and not returned to the same position during the course of the swing, then the path the ball travels as it is struck will usually be at variance from the desired ball path. Normally, it is difficult to determine minor variations in the position of the clubhead both at the address position and as the ball is struck because the clubface is at a considerable distance from the eye, usually between from 5 and 6 feet. This causes clubface positions which are out of alignment with the desired path which, if not corrected, could cause the ball to travel on a path which is at variance with the intended target.
When practicing, a player normally has to rely on his own judgment to determine if the clubface alignment factors described above are correct. Because the game of golf generally requires a repeating swing, errors in alignment and swing tend to feel and look natural after repeated use, and it is difficult, if not impossible, for a player to make his own corrections. Whereas this is true for every type of shot used in playing golf, it is particularly critical in putting where a misalignment of the golf clubhead at impact invariably causes the ball to miss the hole thereby adding an additional stroke to the player's score.
A number of prior art practice devices have been made which attempt to teach a golfer the correct swing and how to develop it. A large group of these are mechanical in nature and must be used adjacent to or in combination with a golf club. These distract a golfer from the execution of a normal stroke and/or provide an environment foreign to actual playing condition. Patented examples of this type of mechanical device used for putting are shown in the patents to Rodman U.S. Pat. Nos. 3,899,180, Donaldson 3,471,155, Berkey 4,082,287 and Kenney 4,129,301.
In addition to the mechanical-type devices of which the above are merely a small representative sample, electrical or electronic devices to aid a player in practicing and developing a proper golf stroke are well known in the art. Most of these are rather complex in nature and require specific installations and environments in order to operate properly. Of these types which use sensors to detect the presence or position of a golf clubhead or struck ball, it is a requirement that the clubhead be placed in a specific position relative to the sensing device in order that some type of interrupt pattern representative of the position of the clubhead be recognized and indicated. Here, also, as with the mechanical devices, the equipment used creates an unnatural environment for the player in the practice mode as compared to the normal playing conditions encountered on a golf course while the playing the game of golf.
Particular reference is made to the patents to Walker U.S. Pat. Nos. 2,571,974, Alvarez 2,825,569, McNeill 3,020,049, Wright 3,601,408, Galasson et al 3,892,414, Goldstein 3,894,739, Morris 3,895,366, and Campbell 3,992,012. A number of these patents operate with light sources and photodetectors wherein the clubhead path or ball interrupts a light source to provide an indication that a ball or clubhead has passed.